Device for the delivery, one by one, of pieces of film from a stack

ABSTRACT

A device for the delivery, one by one, of rectangular pieces of film from a stack, the stack being incorporated in a storage magazine with a substantially flat pressure plate keeping the stack by spring pressure against retaining members acting upon the top film, at least one of the retaining members being a pressure member that can move to and fro near one side of the stack, which pressure member can push one edge of the top film toward the opposite edge, as a result of which the top film is released from the stack over a large part of its surface. The invention being that the direction of active movement of the pressure member coincides with the direction in which the films are delivered, that near the delivery end of the magazine a blocking device is provided which can be moved into the path of the top film, causing it to bulge during the active movement of the pressure member, and that furthermore a second blocking device is provided which, near the end of the active movement of the pressure member, is pressed behind the pushed-up edge of the top film of the stack, and presses it back, counter to the spring force acting upon, to such an extent that the top film is released from the retaining members and after removal of the first blocking device, can extend freely in one direction of delivery.

United States Patent [191 van der Does 1 DEvIcE FOR TIIE DELIVERY, ONE BY ONE, OF PIECES OF FILM FROM A sTAcK [75] Inventor: Lucas van der Does, Delft,

Netherlands [73] Assignee: N.V. Optische lndustrie De Oude Delft, Delft, Netherlands [22] Filed: Dec. 17, 1971 [2l] Appl. No.: 209,119

[30] Foreign Application Priority Data Primary Examiner-Evon C. Blunk Assistant Examiner-James W lvliller V Jan. 15, 1974 [5 7] ABSTRACT A device for the delivery, one by one, of rectangular pieces of film from a stack, the stack being incorporated in a storage magazine with a substantially fiat pressure plate keeping the stack by spring pressure against retaining members acting upon the top film, at least one of the retaining members being a pressure member that can move to and fro near one side of the stack, which pressure member can push one edge of the top film toward the opposite edge, as a result of which the top film is released from the stack over a large part of its surface. The invention being that the direction of active movement of the pressure member coincides with the direction in which the films are delivered, that near the delivery end of the magazine a blocking device is provided which can be moved into the path of the top film, causing it to bulge during the active movement of the pressure member, and that furthermore a second blocking device is provided which, near the end of the active movement of the pressure member, is pressed behind the pushed-up edge of the top film of the stack, and presses it back, counter to the spring force acting upon, to such an extent that the top film is released from the retaining members and after removal of the first blocking device, can extend freely in one direction of delivery.

2 Claims, 5 Drawing Figures 4 7| m 5 I. u H J RU E il N E l A DI.

FIG .1

INVENTOR (/04 5 \fAM deg B ATTORNEY PATENYEDJM 15 I974 sum 0F I FIGJ.

IIIIIlIIIIIIIlIIIIIIIIIIII/II/ I l n n n ATTORNEY DEVICE FOR THE DELIVERY, ONE BY ONE, OF PIECES OF FILM FROM A STACK The invention relates to a device for the delivery, one by one, of rectangular pieces of film from a stack, which stack is incorporated in a storage magazine having a substantially flat pressure plate which keeps the stack pressed by spring pressure against retaining members acting upon the top film, at least one of which retaining members is a pressure member that can move to and fro near one side of the stack, which pressure member can push one edge of the top film toward the opposite edge, as a result of which the top film is released from the stack over a part of its surface.

In known devices of this kind (see German Patent Specification No. 82,431 and Dutch Patent Application No. 70,03121 which is laid open to inspection) there are two pressure members positioned on either side of the stack of films. During their active movement these pressure members press the side edges of the top film toward each other, as a result of which this film is caused to bulge transversely to the direction of delivery. In this way the possibility is afforded of gripping the front or rear edge of the sheet of film that has thus become bulged, using a slide which is provided with a gripping member or hook and which then pulls or pushes the film out of the magazine.

Although the partial bulging of the top sheet of film greatly diminishes the friction of the film with the stack during delivery of the top film, it is constantly proving difficult in practice, even with precise construction, to avoid irregularities. It is probable that these adverse ef fects arise from several contributory factors, one of which is that during delivery of the top film the pack of films remains pressed against the retaining members, so that the top film has to be pulled out from between them; that bulging only occurs at certain spots, and that the films may differ considerably in dimensions, incidental curvature and the like.

The invention aims at providing a device which offers a greater degree of certainty in the film-removing operation than the prior-art devices. For the achievement of this object according to the invention a device of the kind stated in the heading shows the characteristic that the direction of active movement of the pressure member coincides with the direction in which the films are delivered; that near the delivery end of the magazine a first blocking device is provided which can be moved into the path of the top film, causing it to bulge during the active movement of the pressure member, and that furthermore a second blocking device is provided which, near the end of the active movement of the pressure member, is pressed behind the pushed-up edge of the top film of the stack, and presses it back, counter to the spring force acting upon it, to such an extent that the top film is released from the retaining members and, after removal of the first blocking device, can extend freely in the direction of delivery.

In a preferred embodiment of the device according to the invention the two aforementioned blocking devices are positioned at the ends of a rocker.

The pressure member preferably has a surface of I contact with the top film which is provided with a proa way that when the stack is pressed the contact surface lies against the top film.

The invention will be further elucidated by reference to the drawings, in which:

FIG. 1 shows a cross-section of an embodiment of the device according to the invention in accordance with the line I--I in FIG. 2;

FIG. 2 gives a rear view of the embodiment shown in FIG. 1,

FIGS. 3 and 4 show the same cross-section as FIG. 1, in different phases of the film-removing process, whilst FIG. 5 shows a detail of the pressure member.

Item 1 in the FIGS. is the stack of films the top one of which, denoted as 2, has to be delivered to the conveyance rollers 13. The stack rests in a magazine shown in outline, on a pressure plate 3 having in the middle, over its entire breadth, a slight raised part 4 as a result of which the stack of films is to a slight extent preparatorily curved.

The pressure plate 3 is subject to the action of a compression spring 5, via an arm 6 having two pressure points 7 and 8, and thereby keeps the top film 2, when at rest, pressed against retaining members 9 and 10 (see FIGS. l and 2). The retaining members 9 are firmly positioned guide blocks on the delivery side of the magazine. Retainers 10 are situated on the opposite side and are executed in the form of pressure members for bulging the film. For this purpose they are movable in the direction of delivery of the films and are provided with a knife-edge 14 serving to push the top film onward. The knife-blades 14 project to a somewhat lesser extent than the thickness of a film. The pressure members 10 are fixed to arms 22, which are together rotatable around a spindle 24, being guided by a driven cam disk 11, interacting with a roller 23 and a compression spring 12.

Mounted over the magazine is a rocker 16. This rocker can rotate around a spindle 18 and is controlled by the same cam disk 11, which for this purpose interacts with a roller 27 and a compression spring 19. Situated at the ends of the rocker are blocking devices 15 and 17.

In FIG. 1 the pressure members 10 are in the extreme right position, whilst rocker 16 is turned as far as possible to the left. 0n turning the cam disk 11 to the right the pressure member 10 move to the left, during which the knife-edges 14 grip the edge of the top film. As blocking device 15 is now in the delivery path of film 2, the latter becomes bulged, which bulging extends over its entire breadth (see FIG. 3).

Next, under control of the cam disk 11, rocker 16 will turn to the right, as a result of which the second blocking device 17 comes to press behind the edge of film 2 on the stack of films. The first result of this will be that the pushed-up rear edge of film 2 will not be able to fly back when it is released from the knife-edges 14. Moreover, the pressure point of the device 17 lies between the points of application 7 and 8 of lever 6, so that on further rotation of rocker 16 the film pack is pressed slightly downward in a direction approximately parallel to itself. As a result of this the bulged top film 2 is released from the retaining members 9 and 10. As the blocking device 15 is already removed from the path of delivery of the top film, the film can now extend in a forward direction. Then, guided by blocks 9, it comes with its front edge within reach of the conveyance rollers 13, as a result of which it can be further removed (see FIG. 4).

Owing to the fact that the blocking device 17 of rocker 16 keeps the stack of films l clamped against the pressure plate 3, the underlying films will not be carried along with the top film when it extends and is removed.

On further rotation of the cam disk 11 the rocker returns to the initial position of FIG. 1, in which the blocking device 15 is again in the path of delivery of the top film, and the pressure plate 3 again keeps the stack of films pressed against the retaining members 9 and 10.

The pressure members 10 have meanwhile also returned to their initial position, being ready to push the next film onward in the direction of delivery. As shown in FIG. 5 these members preferably consist of a selfadjusting block which can for this purpose tilt around a spindle 21 in arm 22. In front of this spindle 21 a roller 26 runs over the surface of the top film. Behind the tilting spindle the block has contact face 25 the extension of which almost touches roller 26 and from whose face the knife-edge 14 projects.

With this construction, when the pressure member presses against the stack it will invariably adjust itself in such a way that the contact face comes to lie against the film surface. It has been found that in this way the reliability with which the top film is gripped is greatly increased, even if the films concerned are bent or are of unequal size.

What I claim is 1. Apparatus for delivery to a delivery station, one by one, of flexible rectangular pieces of film in a stack, comprising a storage magazine, pressure plate means disposed below and in substantial parallel relation with said stack, a fixed stack retainer member disposed above said stack adjacent said delivery station, at least one movable pressure retainer member positioned above said stack adjacent the edge of said stack remote from said delivery station, spring means urging said plate toward said retainer members normally to press the uppermost sheet of said stack against said retainer members, a pusher member on said movable pressure retainer member positioned to engage the marginal edge of the uppermost film opposite said delivery end, means for shifting said movable retainer member toward said delivery station, a first movable blocking means adjacent said delivery end normally disposed in the path of the lead edge of said top film, said top film being bowed into spaced relation to said stack over a substantial part of its surface responsive to movement of said pressure retainer member toward said delivery end, second blocking means shiftable toward said pressure plate positioned to engage the upper edge of said stack behind said top film following said movement of said pressure member toward said delivery end for shifting said stack away from said retainer members, said stack being clamped between said second blocking means and said pressure plate and released from said retainer members responsive to the movement of said stack by said second blocking means, and means for clearing said first blocking means from said lead edge of said top sheet to permit removal of said top sheet while the remaining sheets of said stack are clamped between said second blocking means and said pressure plate.

2. A device according to claim 1 wherein said pressure retainer member is mounted for pivotal movement about an axis parallel with said marginal edge engaged by said pusher, said retainer member including a roller positioned to engage said top film in leading position relative to said pusher, and a contact face directed toward said stack immediately adjacent said pusher whereby said pressure member is self-adjustably tiltable about said axis to maintain said contact face in engagement with the sheet being fed. i l *8 k 

1. Apparatus for delivery to a delivery station, one by one, of flexible rectangular pieces of film in a stack, comprising a storage magazine, pressure plate means disposed below and in substantial parallel relation with said stack, a fixed stack retainer member disposed above said stack adjacent said delivery station, at least one movable pressure retainer member positioned above said stack adjacent the edge of said stack remote from said delivery station, spring means urging said plate toward said retainer members normally to press the uppermost sheet of said stack against said retainer members, a pusher member on said movable pressure retainer member positioned to engage the marginal edge of the uppermost film opposite said delivery end, means for shifting said movable retainer member toward said delivery station, a first movable blocking means adjacent said delivery end normally disposed in the path of the lead edge of said top film, said top film being bowed into spaced relation to said stack over a substantial part of its surface responsive to movement of said pressure retainer member toward said delivery end, second blocking means shiftable toward said pressure plate positioned to engage the upper edge of said stack behind said top film following said movement of said pressure member toward said delivery end for shifting said stack away from said retainer members, said stack being clamped between said second blocking means and said pressure plate and released from said retainer members responsive to the movement of said stack by said second blocking means, and means for clearing said first blocking means from said lead edge of said top sheet to permit removal of said top sheet while the remaining sheets of said stack are clamped between said second bLocking means and said pressure plate.
 2. A device according to claim 1 wherein said pressure retainer member is mounted for pivotal movement about an axis parallel with said marginal edge engaged by said pusher, said retainer member including a roller positioned to engage said top film in leading position relative to said pusher, and a contact face directed toward said stack immediately adjacent said pusher whereby said pressure member is self-adjustably tiltable about said axis to maintain said contact face in engagement with the sheet being fed. 